An oil pan is typically disposed beneath an engine block and crankshaft of an internal combustion engine, and is configured to receive oil that drains or is otherwise exhausted from the engine block, valvetrain, crankshaft, and/or main bearings that support the crankshaft. The oil collects in a sump of the oil pan and is then pumped from a sump pick-up location into a lubrication system associated with the internal combustion engine.
The rotation of the crankshaft and the reciprocal motion of pistons will cause gases to move within the crankcase, the volume within which the crankshaft is housed, causing turbulence. These turbulent gases may be referred to as “windage.” During operation of the internal combustion engine, some oil that would otherwise drain into the oil pan may instead become entrained in the gases. Accordingly, some vehicle engines include an oil deflector, also referred to as a “windage tray” to separate the crankshaft from the oil pan in order to reduce or eliminate the effects of crankshaft rotation on oil stored or collected in the oil pan. The oil deflector operates to remove oil from the gasses and prevent the entrainment of oil by the gases, which allows the oil to drain back to the sump and be recirculated through the engine's lubrication system. Additionally, the operating efficiency of the internal combustion engine may be reduced due to the inefficient transfer of gases within the crankcase as a result of the pumping action associated with the reciprocal motion of pistons within the internal combustion engine. This gas transfer characteristic is referred to as “bay-to-bay breathing”. The transfer of gases between volumes or bays of the crankcase is often impeded by structural obstructions such as bulkheads, main bearing caps, etc.